Conventionally flanges are included on, for example, metallic hollow structures such as pipes for joining two such structures together or for joining the hollow structure to surrounding structural elements. An example of a conventional flange, can be a disc shaped rim formed on the end of pipes and shafts for coupling them together
In recent times composite materials have become an increasingly attractive alternative to metal for many aircraft components because composite materials offer improved properties such as lower weight, improved fatigue/damage resistance, corrosion resistance and negligible thermal expansion. In terms of manufacture, a flange that forms a disc shaped rim made from composite materials can be a very complex manufacturing process due to the uniformity of fibre alignment being important in the flange that is load bearing in application.
Due to the complexities in manufacturing a composite flange, aircraft components requiring such a configuration are commonly made from metal.